This project provides software for plugging a Teensy 3.x into LinuxCNC's HAL. It supports digital inputs and outputs, analog input, analog output (via the Teensy DAC) and PWM output (via the Teensy "analog output" pins).
This project was forked from apmorton's teensy-template, https://github.com/apmorton/teensy-template
Install the Teensy udev rule: sudo cp tools/49-teensy.rules /etc/udev/rules.d/
Then unplug your Teensy and plug it back in.
Possibly edit the TEENSY variable in the Makefile to set your Teensy version (3.0 or 3.1).
Run make upload to compile the firmware and upload it to the Teensy.
Run ./hal-teensy to start the hal driver (linuxcnc must be running
for this to work).
The Teensy and the PC trade packets with 3 bits of address and 16 bits of data, using this format:
byte 0: 0 A02 A01 A00 D15 D14 D13 D12
byte 1: 1 0 D11 D10 D09 D08 D07 D06
byte 2: 1 1 D05 D04 D03 D02 D01 D00
The leading bits make the protocol self-synchronizing. Inspired by Jeff Epler's Arduino/HAL protocol: http://emergent.unpythonic.net/01198594294
0: digital inputs, D00-D07, Teensy pins 0-6
1: analog input 0, 16 bits resolution, Teensy pin A0
2: analog input 1, 16 bits resolution, Teensy pin A1
0: digital outputs, D00-D07, Teensy pins 7-13 (LED on pin 13)
1: DAC 0, 12 bits resolution, D04-D15 used, D00-D03 ignored, Teensy pin A14
2: PWM 0, 8 bits resolution, 2048 ns period, D00-D07, Teensy pin 20
3: PWM 1, 8 bits resolution, 2048 ns period, D00-D07, Teensy pin 21
4: PWM 2, 8 bits resolution, 2048 ns period, D00-D07, Teensy pin 22
5: PWM 3, 8 bits resolution, 2048 ns period, D00-D07, Teensy pin 23